Patent Document 1 discloses a system configured to transfer electric power through capacitive coupling.
The power transfer system described in Patent Document 1 comprises: a power transmission device including a high-frequency high-voltage generator, and a passive electrode and an active electrode which form generating electrodes; and a power reception device including a high-frequency high-voltage load, and a passive electrode and an active electrode which form electromotive electrodes.
The electrodes referred to as “generating electrodes” generate a field. The electrodes referred to as “electromotive electrodes” receive the field.
The passive electrode of the generating electrodes is applied with a lower voltage than the active electrode of the generating electrodes. The passive electrode of the electromotive electrodes is applied with a lower voltage than the active electrode of the electromotive electrodes.
The high-frequency voltage used in this system has a frequency ranging from 10 kHz to 10 MHz and a voltage ranging from 100 V to 10 kV for home appliance devices to several hundred of kilovolts or more for automotive or industrial devices. When the frequency of the high-frequency voltage is within this range, the device does not radiate energy in the form of electromagnetic waves, and an electrostatic field is generated in a surrounding medium because the wavelength (lambda) in the surrounding medium is large enough relative to the size D of the device, or D<<(lambda).
FIG. 1 is a view illustrating the basic configuration of the power transfer system of Patent Document 1. The power transmission device includes a high-frequency high-voltage generator 1, and a passive electrode 2 and an active electrode 3 which form the generating electrodes. The power reception device includes a high-frequency high-voltage load 5, and a passive electrode 7 and an active electrode 6 which form the electromotive electrodes. The active electrode 3 of the power transmission device and the active electrode 6 of the power reception device are surrounded by a high electric field area 4. The power transmission device and the power reception device are capacitively coupled through the generating and electromotive electrodes and the surrounding dielectric medium.    Patent Document 1: National Publication of International Patent Application No. 2009-531009